The kingdom of God is not a matter of eating or drinking, but of justice, peace, and the joy that is given by the Holy Spirit. Whoever serves Christ in this way pleases God and wins the esteem of men. Let us, then, make it our aim to work for peace and to strengthen one another.
Another way this reads is:
For the kingdom of God is not food and drink but righteousness and peace and joy in the Holy Spirit; he who thus serves Christ is acceptable to God and approved by men. Let us then pursue what makes for peace and for mutual upbuilding.
In any event, we see that this says alot about what Christian life is and is not. First, the kingdom of God is not about eating and drinking. It is not about the friendship and the fellowship we experience with others. Those things are good and inevitably flow from a Christian life, but they are not what the kingdom of God is about, because these things can come from outside the kingdom of God as well. God’s purpose is not simply so that we can enjoy ourselves, but it really is to honor him and live in him. Living in him involves righteousness or justice, the thing St. Paul mentions first. That is that we live in accord with the will of God. We are obedient to him and we love him and love our neighbor. We feed the hungry, clothe the poor, visit the lonely. We worship our God, come to his Sacraments, and spend time with him in prayer. Second we are to be peacemakers. We, as Baptized Christians, have the power of the Spirit in us making us quite fruitful. We bring peace and hope to people by speaking words of life to them, lifting them from this world to the next, where the only peace in this universe can be found. Thirdly, we live in the joy of the Spirit. No matter what our Cross brings us, we live in joy because we know that this Cross we bear is not all that there is, that this life is not the end.
When we live in this way and serve in this manner, we become acceptable to Christ. We may think that we can never be acceptable to Christ, but St. Paul tells us right here that we can be and how we can be. If we serve Jesus this way God will see us as a beautiful oblation. Not only that, but men will see us in a positive light. Even though the world hates Catholicism, they love the uber Catholic among us, those who do more than just talk-the-talk, but those who walk-the-walk, the Mother Theresa’s among us.
These are the simple things that God requires of us. And so to become pleasing to God we seek peace and work to build each other up, both Catholics and non-Catholics, both spiritually and physically. In doing so, we become little icons, little mirrors of Jesus himself, becoming capable of and worthy of receiving the unending and burning divine love of God the Father.